Specification for Structural Steel Buildings

612 Pages·2011·4.97 MB·English

ANSI/AISC 360-10
An American National Standard
Specification
for Structural Steel Buildings
June 22, 2010
Supersedes the
Specification for Structural Steel Buildings
dated March 9, 2005
and all previous versions of this specification
Approved by the AISC Committee on Specifications
AMERICAN INSTITUTE OF STEEL CONSTRUCTION
One East Wacker Drive, Suite 700
Chicago, Illinois 60601-1802
AISC © 2010
by
American Institute of Steel Construction
All rights reserved. This book or any part thereof
must not be reproduced in any form without the
written permission of the publisher.
The AISC logo is a registered trademark of AISC.
The information presented in this publication has been prepared in accordance with recog-
nized engineering principles and is for general information only. While it is believed to be
accurate, this information should not be used or relied upon for any specific application
without competent professional examination and verification of its accuracy, suitability and
applicability by a licensed professional engineer, designer or architect. The publication of
the material contained herein is not intended as a representation or warranty on the part of
the American Institute of Steel Construction or of any other person named herein, that this
information is suitable for any general or particular use or of freedom from infringement of
any patent or patents. Anyone making use of this information assumes all liability arising
from such use.
Caution must be exercised when relying upon other specifications and codes developed by
other bodies and incorporated by reference herein since such material may be modified or
amended from time to time subsequent to the printing of this edition. The Institute bears no
responsibility for such material other than to refer to it and incorporate it by reference at the
time of the initial publication of this edition.
Printed in the United States of America
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION
16.1–iii
PREFACE
(This Preface is not part of ANSI/AISC 360-10, Specification for Structural Steel Buildings,
but is included for informational purposes only.)
This Specification is based upon past successful usage, advances in the state of knowledge,
and changes in design practice. The 2010 American Institute of Steel Construction’s
Specification for Structural Steel Buildings provides an integrated treatment of allowable
stress design (ASD) and load and resistance factor design (LRFD), and replaces earlier
Specifications. As indicated in Chapter B of the Specification, designs can be made accord-
ing to either ASD or LRFD provisions.
This Specification has been developed as a consensus document to provide a uniform
practice in the design of steel-framed buildings and other structures. The intention is to pro-
vide design criteria for routine use and not to provide specific criteria for infrequently
encountered problems, which occur in the full range of structural design.
This Specification is the result of the consensus deliberations of a committee of structural
engineers with wide experience and high professional standing, representing a wide geo-
graphical distribution throughout the United States. The committee includes approximately
equal numbers of engineers in private practice and code agencies, engineers involved in
research and teaching, and engineers employed by steel fabricating and producing compa-
nies. The contributions and assistance of more than 50 additional professional volunteers
working in ten task committees are also hereby acknowledged.
The Symbols, Glossary and Appendices to this Specification are an integral part of the
Specification. A non-mandatory Commentary has been prepared to provide background for
the Specification provisions and the user is encouraged to consult it. Additionally, non-
mandatory User Notes are interspersed throughout the Specification to provide concise and
practical guidance in the application of the provisions.
The reader is cautioned that professional judgment must be exercised when data or rec-
ommendations in the Specification are applied, as described more fully in the disclaimer
notice preceding this Preface.
This Specification was approved by the Committee on Specifications:
James M. Fisher, Chairman Louis F. Geschwindner
Edward E. Garvin, Vice Chairman Lawrence G. Griffis
Hansraj G. Ashar John L. Gross
William F. Baker Jerome F. Hajjar
John M. Barsom Patrick M. Hassett
William D. Bast Tony C. Hazel
Reidar Bjorhovde Mark V. Holland
Roger L. Brockenbrough Ronald J. Janowiak
Gregory G. Deierlein Richard C. Kaehler
Bruce R. Ellingwood Lawrence A. Kloiber
Michael D. Engelhardt Lawrence F. Kruth
Shu-Jin Fang Jay W. Larson
Steven J. Fenves Roberto T. Leon
John W. Fisher James O. Malley
Theodore V. Galambos Sanjeev R. Malushte
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION
16.1–iv PREFACE
David L. McKenzie Robert E. Shaw, Jr.
Duane K. Miller Donald R. Sherman
Larry S. Muir W. Lee Shoemaker
Thomas M. Murray William A. Thornton
R. Shankar Nair Raymond H. R. Tide
Jack E. Petersen Chia-Ming Uang
Douglas A. Rees-Evans Donald W. White
Thomas A. Sabol Cynthia J. Duncan, Secretary
The Committee gratefully acknowledges the following task committee members and staff
for their contribution to this document:
Allen Adams Brent Leu
Farid Alfawakhiri J. Walter Lewis
Susan Burmeister William Lindley
Bruce M. Butler Stanley Lindsey
Charles J. Carter LeRoy Lutz
Helen Chen Bonnie Manley
Bernard Cvijanovic Peter Marshall
Robert Disque Margaret Matthew
Carol Drucker Curtis L. Mayes
W. Samuel Easterling William McGuire
Duane Ellifritt Saul Mednick
Marshall T. Ferrell James Milke
Christopher M. Foley Heath Mitchell
Steven Freed Patrick Newman
Fernando Frias Jeffrey Packer
Nancy Gavlin Frederick Palmer
Amanuel Gebremeskel Dhiren Panda
Rodney D. Gibble Teoman Pekoz
Subhash Goel Clarkson Pinkham
Arvind Goverdhan Thomas Poulos
Kurt Gustafson Christopher Raebel
Tom Harrington Thomas D. Reed
Todd Helwig Clinton Rex
Richard Henige Benjamin Schafer
Stephen Herlache Thomas Schlafly
Steve Herth Monica Stockmann
Keith Hjelmstad James Swanson
Nestor Iwankiw Steven J. Thomas
William P. Jacobs, V Emile Troup
Matthew Johann Brian Uy
Daniel Kaufman Amit H. Varma
Keith Landwehr Sriramulu Vinnakota
Barbara Lane Ralph Vosters
Michael Lederle Robert Weber
Roberto Leon Michael A. West
Andres Lepage Ronald D. Ziemian
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION
16.1–v
TABLE OF CONTENTS
SYMBOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii
GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xliii
SPECIFICATION
A. GENERAL PROVISIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
A1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1. Seismic Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Nuclear Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
A2. Referenced Specifications, Codes and Standards . . . . . . . . . . . . . . . . . . . . . . . 2
A3. Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Structural Steel Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1a. ASTM Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1b. Unidentified Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1c. Rolled Heavy Shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1d. Built-Up Heavy Shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2. Steel Castings and Forgings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Bolts, Washers and Nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. Anchor Rods and Threaded Rods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Consumables for Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6. Headed Stud Anchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
A4. Structural Design Drawings and Specifications . . . . . . . . . . . . . . . . . . . . . . . . 9
B. DESIGN REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
B1. General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
B2. Loads and Load Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
B3. Design Basis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1. Required Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2. Limit States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3. Design for Strength Using Load and Resistance Factor Design
(LRFD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4. Design for Strength Using Allowable Strength Design (ASD) . . . . . . . . 11
5. Design for Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6. Design of Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6a. Simple Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6b. Moment Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7. Moment Redistribution in Beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8. Diaphragms and Collectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
9. Design for Serviceability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
10. Design for Ponding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
11. Design for Fatigue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
12. Design for Fire Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION
16.1–vi TABLE OF CONTENTS
13. Design for Corrosion Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
14. Anchorage to Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
B4. Member Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Classification of Sections for Local Buckling . . . . . . . . . . . . . . . . . . . . . 14
1a. Unstiffened Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1b. Stiffened Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2. Design Wall Thickness for HSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3. Gross and Net Area Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3a. Gross Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3b. Net Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
B5. Fabrication and Erection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
B6. Quality Control and Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
B7. Evaluation of Existing Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
C. DESIGN FOR STABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
C1. General Stability Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1. Direct Analysis Method of Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2. Alternative Methods of Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
C2. Calculation of Required Strengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1. General Analysis Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2. Consideration of Initial Imperfections . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2a. Direct Modeling of Imperfections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2b. Use of Notional Loads to Represent Imperfections . . . . . . . . . . . . . . . . . 22
3. Adjustments to Stiffness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
C3. Calculation of Available Strengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
D. DESIGN OF MEMBERS FOR TENSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
D1. Slenderness Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
D2. Tensile Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
D3. Effective Net Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
D4. Built-Up Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
D5. Pin-Connected Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1. Tensile Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2. Dimensional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
D6. Eyebars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
1. Tensile Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2. Dimensional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
E. DESIGN OF MEMBERS FOR COMPRESSION . . . . . . . . . . . . . . . . . . . . . . . . 31
E1. General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
E2. Effective Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
E3. Flexural Buckling of Members without Slender Elements . . . . . . . . . . . . . . . 33
E4. Torsional and Flexural-Torsional Buckling of Members Without
Slender Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
E5. Single Angle Compression Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION
TABLE OF CONTENTS 16.1–vii
E6. Built-Up Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
1. Compressive Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2. Dimensional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
E7. Members with Slender Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
1. Slender Unstiffened Elements, Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
s
2. Slender Stiffened Elements, Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
a
F. DESIGN OF MEMBERS FOR FLEXURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
F1. General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
F2. Doubly Symmetric Compact I-Shaped Members and Channels Bent
About Their Major Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
F3. Doubly Symmetric I-Shaped Members With Compact Webs and
Noncompact or Slender Flanges Bent About Their Major Axis . . . . . . . . . . . 49
1. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2. Compression Flange Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
F4. Other I-Shaped Members With Compact or Noncompact Webs Bent
About Their Major Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
1. Compression Flange Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3. Compression Flange Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4. Tension Flange Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
F5. Doubly Symmetric and Singly Symmetric I-Shaped Members With
Slender Webs Bent About Their Major Axis . . . . . . . . . . . . . . . . . . . . . . . . . . 54
1. Compression Flange Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3. Compression Flange Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4. Tension Flange Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
F6. I-Shaped Members and Channels Bent About Their Minor Axis . . . . . . . . . . 55
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2. Flange Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
F7. Square and Rectangular HSS and Box-Shaped Members . . . . . . . . . . . . . . . . 56
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2. Flange Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
3. Web Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
F8. Round HSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2. Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
F9. Tees and Double Angles Loaded in the Plane of Symmetry . . . . . . . . . . . . . . 58
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3. Flange Local Buckling of Tees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4. Local Buckling of Tee Stems in Flexural Compression . . . . . . . . . . . . . 59
Specification for Structural Steel Buildings, June 22, 2010
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16.1–viii TABLE OF CONTENTS
F10. Single Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3. Leg Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
F11. Rectangular Bars and Rounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
F12. Unsymmetrical Shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
1. Yielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
2. Lateral-Torsional Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3. Local Buckling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
F13. Proportions of Beams and Girders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
1. Strength Reductions for Members With Holes in the
Tension Flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
2. Proportioning Limits for I-Shaped Members . . . . . . . . . . . . . . . . . . . . . . 64
3. Cover Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4. Built-Up Beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5. Unbraced Length for Moment Redistribution . . . . . . . . . . . . . . . . . . . . . 66
G. DESIGN OF MEMBERS FOR SHEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
G1. General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
G2. Members With Unstiffened or Stiffened Webs . . . . . . . . . . . . . . . . . . . . . . . . 67
1. Shear Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
2. Transverse Stiffeners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
G3. Tension Field Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
1. Limits on the Use of Tension Field Action . . . . . . . . . . . . . . . . . . . . . . . 70
2. Shear Strength With Tension Field Action . . . . . . . . . . . . . . . . . . . . . . . 70
3. Transverse Stiffeners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
G4. Single Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
G5. Rectangular HSS and Box-Shaped Members . . . . . . . . . . . . . . . . . . . . . . . . . .71
G6. Round HSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
G7. Weak Axis Shear in Doubly Symmetric and Singly
Symmetric Shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
G8. Beams and Girders with Web Openings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
H. DESIGN OF MEMBERS FOR COMBINED FORCES
AND TORSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
H1. Doubly and Singly Symmetric Members Subject to Flexure
and Axial Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
1. Doubly and Singly Symmetric Members Subject to Flexure
and Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
2. Doubly and Singly Symmetric Members Subject to Flexure
and Tension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
3. Doubly Symmetric Rolled Compact Members Subject to
Single Axis Flexure and Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION
TABLE OF CONTENTS 16.1–ix
H2. Unsymmetric and Other Members Subject to Flexure
and Axial Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
H3. Members Subject to Torsion and Combined Torsion, Flexure,
Shear and/or Axial force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
1. Round and Rectangular HSS Subject to Torsion . . . . . . . . . . . . . . . . . . . 77
2. HSS Subject to Combined Torsion, Shear, Flexure
and Axial Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
3. Non-HSS Members Subject to Torsion and Combined Stress . . . . . . . . 79
H4. Rupture of Flanges With Holes Subject to Tension . . . . . . . . . . . . . . . . . . . . . 79
I. DESIGN OF COMPOSITE MEMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
I1. General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
1. Concrete and Steel Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
2. Nominal Strength of Composite Sections . . . . . . . . . . . . . . . . . . . . . . . . 82
2a. Plastic Stress Distribution Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
2b. Strain Compatibility Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3. Material Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
4. Classification of Filled Composite Sections for Local Buckling . . . . . . 83
I2. Axial Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
1. Encased Composite Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
1a. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
1b. Compressive Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
1c. Tensile Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
1d. Load Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
1e. Detailing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2. Filled Composite Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2a. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2b. Compressive Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
2c. Tensile Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
2d. Load Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
I3. Flexure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
1a. Effective Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
1b. Strength During Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
2. Composite Beams With Steel Headed Stud or Steel
Channel Anchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
2a. Positive Flexural Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
2b. Negative Flexural Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
2c. Composite Beams With Formed Steel Deck . . . . . . . . . . . . . . . . . . . . . . 90
2d. Load Transfer Between Steel Beam and Concrete Slab . . . . . . . . . . . . . 90
3. Encased Composite Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
4. Filled Composite Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
4a. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
4b. Flexural Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION
16.1–x TABLE OF CONTENTS
I4. Shear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
1. Filled and Encased Composite Members . . . . . . . . . . . . . . . . . . . . . . . . . 93
2. Composite Beams With Formed Steel Deck . . . . . . . . . . . . . . . . . . . . . . 93
I5. Combined Flexure and Axial Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
I6. Load Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
1. General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
2. Force Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
2a. External Force Applied to Steel Section . . . . . . . . . . . . . . . . . . . . . . . . . 94
2b. External Force Applied to Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
2c. External Force Applied Concurrently to Steel and Concrete . . . . . . . . . 94
3. Force Transfer Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
3a. Direct Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
3b. Shear Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
3c. Direct Bond Interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
4. Detailing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4a. Encased Composite Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4b. Filled Composite Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
I7. Composite Diaphragms and Collector Beams . . . . . . . . . . . . . . . . . . . . . . . . . 96
I8. Steel Anchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
2. Steel Anchors in Composite Beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
2a. Strength of Steel Headed Stud Anchors . . . . . . . . . . . . . . . . . . . . . . . . . . 97
2b. Strength of Steel Channel Anchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
2c. Required Number of Steel Anchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
2d. Detailing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
3. Steel Anchors in Composite Components . . . . . . . . . . . . . . . . . . . . . . . .100
3a. Shear Strength of Steel Headed Stud Anchors in
Composite Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
3b. Tensile Strength of Steel Headed Stud Anchors in
Composite Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
3c. Strength of Steel Headed Stud Anchors for Interaction of Shear
and Tension in Composite Components . . . . . . . . . . . . . . . . . . . . . . . . 102
3d. Shear Strength of Steel Channel Anchors in
Composite Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
3e. Detailing Requirements in Composite Components . . . . . . . . . . . . . . . 104
I9. Special Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
J. DESIGN OF CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
J1. General Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
1. Design Basis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
2. Simple Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
3. Moment Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
4. Compression Members With Bearing Joints . . . . . . . . . . . . . . . . . . . . . 106
5. Splices in Heavy Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Specification for Structural Steel Buildings, June 22, 2010
AMERICANINSTITUTEOFSTEELCONSTRUCTION